A series of 4-aryl-3,4-dihydropyrimidin-2(1H)-(thi)one derivatives were synthesized. The anticonvulsant effect and neurotoxicity of the compounds were calculated with maximal electroshock (MES) test, subcutaneous pentylenetetrazole (sc-PTZ) and rotarod tests via intraperitoneally in mice. In the anti-MES potency test, it showed that 4-o-cloride-aryl-3,4- dihydropyrimidin-2(1H)-one (4g) was found to be the most potent with ED50 value of 64.3mg/kg and protective index (PI = TD50/ED50) value of 9.5, which was greater than PI of the prototype drug phenytoin.